1. Field of the Invention
The present invention relates generally to communication networks that include attached printers for printing of bar code labels, and more particularly, to a proxy device coupled to the network for use with a bar code label printer to enable encoding of radio frequency identification tags embedded in bar code label print stock.
2. Description of Related Art
In the automated identification and data capture industry, it is known to operate a local area network (LAN) that enables communication between a central host computer and a plurality of devices, such as printers, bar code readers, data entry terminals, and the like. The LAN may further include interconnected wired and/or wireless networks that together support communication within an enterprise. Communication cells established by wireless access points provide links between network elements connected to the wired backbone and mobile terminals. Within the LAN, operators may utilize handheld data-collection terminals to communicate with the central host computer. The data-collection terminals enable the operators to scan and decode data that may be encoded in the form of a one or two-dimensional bar code symbol. The decoded information is then transmitted back to the central host computer across the RF channel. Such wireless LAN systems are particularly well suited to data capture applications as diverse as process and inventory control, time and attendance monitoring, security management, customer service and point of sale recording, shipping and receiving record keeping, and warehouse operations.
The LAN may further include one or more printers for producing bar code labels used in identifying items that are tracked in a particular data capture application. The printers may be adapted to print individual labels on demand, or to print a series of labels in a single continuous run. In order for the data-collection terminal to accurately read the bar code symbol, it is essential that the symbol be printed in a high quality manner, without any streaking, blurring or improper registration of the symbols to the labels. At the same time, it is essential that the adhesive backing layer of the labels not be damaged by heat generated during the printing process. In view of the demanding printing requirements, bar code symbols are often printed using direct thermal or thermal transfer printing techniques, referred to collectively herein as thermal printing. To achieve maximum data throughput, dedicated thermal printers are generally coupled to the central host computer either directly or through a dedicated print server.
Increasingly, it is desirable to further equip these networks with an ability to utilize radio frequency identification (RFID) systems. An RFID tag generally includes a semiconductor memory in which information may be stored. A data collection terminal that includes an RFID interrogator is used to query an RFID tag that may be at a distance from the interrogator and moving at highway speeds. The RFID tag detects the interrogating signal and transmits a response signal containing encoded data back to the interrogator. Such RFID tags may have a memory capacity of several kilobytes or more, which is substantially greater than the maximum amount of data that may be contained in a bar code symbol or other types of human-readable indicia. Further, the RFID tag memory may be re-written with new or additional data, which would not be possible with a printed bar code symbol. RFID tags may also be readable at a distance without requiring a direct line-of-sight view by the RFID interrogator, unlike bar code symbols or other types of human-readable indicia that must be within a direct line-of-sight and which may be rendered entirely unreadable if obscured or damaged.
In view of the additional benefits of RFID tags, it is known to incorporate RFID tags into the bar code label print stock that is loaded into the network printers. Special purpose printers are adapted to print human-readable indicia and bar code symbols onto the label print stock, while at the same time an embedded RFID interrogator encodes associated data into the RFID tag memory. The printed and encoded label then serves dual purposes, i.e., it can be read by a data collection terminal having either optical scanning or RFID interrogating capability. This provides significant additional benefit for the user, and allows the user to transition from an existing bar-code based data collection capability to an RFID based data collection capability.
Notwithstanding these benefits of adding embedded RFID tags into bar code label print stock, there is a considerable cost associated with the special purpose printers and other equipment needed to implement an RFID capability. Users that have already invested significant sums in purchasing high capacity bar code label printers and associated drivers and equipment are understandably reluctant to scrap their existing systems in favor of new dual mode equipment. This has resulted in delayed adoption of RFID systems by many businesses that would otherwise benefit from RFID technology.
Accordingly, it would be desirable to provide a conventional bar code printer with an ability to encode RFID tags embedded in the bar code label print stock.